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Seat No.: ________ Enrolment No.___________

GUJARAT TECHNOLOGICAL UNIVERSITY BE – SEMESTER–VIII • Remedial EXAMINATION – WINTER 2013

Subject Code: 180906 Date: 12/09/2013 Subject Name: Advanced Power System - II Time: 03:00 pm – 05:30 pm Total Marks: 70 Instructions:

1. Attempt all questions. 2. Make suitable assumptions wherever necessary. 3. Figures to the right indicate full marks.

Q.1 (a) For a transmission line connected between two buses, derive the expression

of voltage regulation and also establish from the phasor diagram and the equations that the Q and V have a strong coupling.

07

(b) Explain system state classification with relevant figure clearly indicating all security levels and transition between different security levels.

07

Q.2 (a) Describe Least Square Estimation (LSE) and Weighted LSE for estimation of

x (vector of n random variables) using another vector y of variables m (>n). 07

(b) In relation to state estimation process, explain detection, identification and suppression of bad data in the measurement vector.

07

OR (b) Explain various applications of state estimations in a power system. 07

Q.3 (a) Explain in detail as related to power system security: 1. System monitoring 2. Contingency Analysis

07

(b) Differentiate between normal, alert and emergency state of a power system. Explain emergency control in brief.

07

OR Q.3 (a) Explain generation shift factor and line outage distribution factor in relation

to security analysis. How they are helpful in security analysis?07

(b) What is black-out in a power system? When can it occur? Explain power system restoration after black-out.

07

Q.4 (a) Enlist different types of reactive power compensation methods for heavily

loaded and voltage stressed power systems. Explain static VAR compensators in detail.

07

(b) What is voltage collapse? Explain the main factors that contribute to the phenomena of voltage collapse.

07

OR Q.4 (a) Derive the expression of critical voltage and critical angle at receiving end at

voltage stability limit for two bus system.07

(b) What is voltage stability? Explain different types of voltage stability. 07 Q.5 (a) Explain the structure of deregulated electric industry. How does it differ from

vertically integrated electric industry?07

(b) Write short note on load forecasting. 07 OR

Q.5 (a) Write a short note on The Electricity Act – 2003. 07 (b) Explain load forecasting methodology and estimation of average and

trend terms. 07

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